FRIEDRICH [III] von Vianden, son of FRIEDRICH [II] Graf von Vianden & his wife Elisabeth von Salm (-after 1200). Graf von Vianden. Gerhard Abbot of Prüm confirmed that "comes Vianensis Fridericus junior filius fratris mei Friderici comitis" had resigned the patronat of Alf church, at the request of "uxoris sue Matilde" by charter dated 1187, witnessed by "…Fridericus comes, Heremannus frater eius…"[345]. He founded Kloster Niederehe. "Elysa…comitissa Salmensis…consensu filiorum nostrorum" donated "ius patronatus ecclesie Sigendorf" to Kloster Niederprüm by charter dated 1200 witnessed by "Gerardo Prumiensi abbate, Willelmo decano maioris ecclesie Treverensis, Friderico comite Viennensi…Mehthildi comitissa Viennensi"[346].
m (before 1187) MECHTILD von der Neuerburg, daughter of ---. Gerhard Abbot of Prüm confirmed that "comes Vianensis Fridericus junior filius fratris mei Friderici comitis" had resigned the patronat of Alf church, at the request of "uxoris sue Matilde" by charter dated 1187, witnessed by "…Fridericus comes, Heremannus frater eius…"[347]. "Elysa…comitissa Salmensis…consensu filiorum nostrorum" donated "ius patronatus ecclesie Sigendorf" to Kloster Niederprüm by charter dated 1200 witnessed by "Gerardo Prumiensi abbate, Willelmo decano maioris ecclesie Treverensis, Friderico comite Viennensi…Mehthildi comitissa Viennensi"[348].
Friedrich [III] & his wife had four children